This is kind of a long read, but definitely Instapaper material. It's a transcript from Keith's speech from the Fronteers conference 2010. If you're going to read just a couple of pieces about HTML5, make sure you get this one. He brings up history of HTML and XHTML – a story about agony, betrayal and markup. He talks about the simplicity in HTML5 (the doctype!) and how we can solve the common problems we had in XHTML 1.0 with the new spec. If you're into details and nitty-gritty stuff like I am, go read this.